Rice cultivar ‘UADA1701081’

ABSTRACT

A rice cultivar designated UADA1701081 is disclosed herein. The present invention provides seeds, plants, and plant parts derived from rice cultivar UADA1701081. Further, it provides methods for producing a rice plant by crossing UADA1701081 with itself or another rice variety. The invention also encompasses any rice seeds, plants, and plant parts produced by the methods disclosed herein, including those in which additional traits have been transferred into UADA1701081 through the introduction of a transgene or by breeding UADA1701081 with another rice cultivar.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive rice cultivar, designated UADA1701081.

Rice is an ancient agricultural crop and is today one of the principal food crops of the world. There are two cultivated species of rice: Oryza sativa L., the Asian rice, and O. glaberrima Steud., the African rice. O. sativa L. constitutes virtually all of the world's cultivated rice and is the species grown in the United States. Three major rice producing regions exist in the United States: the Mississippi Delta (Arkansas, Mississippi, northeast Louisiana, southeast Missouri), the Gulf Coast (southwest Louisiana, southeast Texas), and the Central Valleys of California.

Rice is a semi-aquatic crop that benefits from flooded soil conditions during part or all of the growing season. In the United States, rice is grown on flooded soils to optimize grain yields. Heavy clay soils or silt loam soils with hard pan layers about 30 cm below the surface are preferred rice-producing soils because they minimize water losses from soil percolation. Rice production in the United States can be broadly categorized as either dry-seeded or water-seeded. In the dry-seeded system, rice is sown into a well-prepared seed bed with a grain drill or by broadcasting the seed and incorporating it with a disk or harrow. Moisture for seed germination is provided by irrigation or rainfall. Alternatively, the seed may be broadcast by airplane into a flooded field, which is promptly drained following seeding. With the dry-seeded system, when the plants have reached sufficient size (four- to five-leaf stage), a shallow permanent flood of water, 5 to 16 cm deep, is applied to the field for the remainder of the crop season.

In the water-seeded system, rice seed is soaked for 12 to 36 hours to initiate germination, and the seed is broadcast by airplane into a flooded field. The seedlings emerge through a shallow flood, or the water may be drained from the field for a short period of time to enhance seedling establishment. A shallow flood is maintained until the rice approaches maturity. For both the dry-seeded and water-seeded production systems, the fields are drained when the crop is mature, and the rice is harvested 2 to 3 weeks later with large combines. In rice breeding programs, breeders typically employ the production systems predominant in their respective region. Thus, a drill-seeded breeding nursery is used by breeders in a region where rice is drill-seeded and a water-seeded nursery is used in regions where water-seeding is prominent.

Rice in the United States is classified into three primary market types by grain size, shape, and chemical composition of the endosperm: long-grain, medium-grain and short-grain. Typical U.S. long-grain cultivars cook dry and fluffy when steamed or boiled, whereas medium and short-grain cultivars cook moist and sticky. Traditionally, in the southern states, long-grain cultivars have been grown and generally receive higher market prices.

Rice, Oryza sativa L., is an important and valuable field crop. A continuing goal of plant breeders is to produce stable, high yielding rice cultivars that are agronomically sound. To accomplish this goal, rice plants with traits that result in superior cultivars must be developed.

SUMMARY OF THE INVENTION

The present invention provides a novel rice cultivar designated UADA1701081. The invention encompasses the seeds, plants, and plant parts of rice cultivar UADA1701081, as well as plants with essentially all of the physiological and morphological characteristics of UADA1701081.

This invention also provides methods for producing a rice plant by planting a plurality of seeds or by crossing rice UADA1701081 with itself or another rice line. Any plant breeding methods using rice cultivar UADA1701081 are part of this invention, including selfing, backcrosses, hybrid production, and crosses to populations. All plants and seeds produced using rice cultivar UADA1701081 as a parent are within the scope of this invention, including gene-converted plants of UADA1701081. Methods for introducing a gene into UADA1701081, either through traditional breeding or transformation, are provided herein.

In still another aspect, the present invention provides regenerable cells for use in tissue culture of rice plant UADA1701081, as well as rice plants regenerated from these tissue cultures.

Definitions

To provide a clear and consistent understanding of the specification and claims, the following definitions are provided:

Apparent starch amylose content. The amount of starch in the endosperm of milled rice that is amylose, provided in g/kg herein. Amylose content varies depending on the growth environment of the rice. It is an important grain characteristic used to describe cooking behavior.

Backcrossing. A process in which a breeder repeatedly crosses hybrid progeny back to a parental line. For example, a first generation (F₁) hybrid may be crossed with one of the parental lines used to produce the F₁ hybrids.

Breeding. The genetic manipulation of living organisms.

Cell. As used herein, this term includes isolated cells, cells grown in tissue culture, and cells that comprise a plant or plant part.

Cultivar. Used interchangeably with “variety”. Refers to plants that are defined by the expression of the characteristics resulting from a given genotype or combination of genotypes, distinguished from any other plant grouping by the expression of at least one characteristic.

Days to 50% heading. The average number of days from emergence to the day when 50% of all panicles are exerted at least partially through the leaf sheath. A measure of maturity.

Embryo. The plant embryo is the part of a seed or bud that contains the earliest forms of the new plant's roots, stem and leaves.

Essentially all of the physiological and morphological characteristics. A plant having “essentially all the physiological and morphological characteristics” of the cultivar exhibits the characteristics of the cultivar with the exception of any characteristics derived from a converted gene.

F#. Denotes a filial generation, wherein the # is the generation number. For example, F1 is the first filial generation.

Gene. Refers to a unit of inheritance corresponding to a distinct sequence of DNA or

RNA nucleotides that form part of a chromosome. A gene may encode a polypeptide or a nucleic acid molecule that has a function in the cell or organism.

Gene-converted. Describes a plant wherein essentially all of the desired morphological and physiological characteristics of a parental variety are maintained with the exception of a single trait that was transferred into the variety via backcrossing or genetic engineering.

Genotype. Refers to the genetic constitution of a cell or organism.

Grain yield. Measured in pounds per acre at 12.0% moisture content. The grain yield of rice is determined by the number of panicles per unit area, the number of fertile florets per panicle, and the grain weight per floret.

Haploid. A cell or organism having a single set of unpaired chromosomes.

Head rice. Kernels of milled rice in which greater than ¾ of the kernel is unbroken.

Herbicide resistant. Describes a plant that is tolerant or resistant to an herbicide at a level that would normally kill or inhibit the growth of a normal or wild-type rice plant.

Hybrid. Refers to the offspring or progeny of genetically dissimilar plant parents or stock produced as the result of controlled cross-pollination as opposed to a non-hybrid seed produced as the result of natural pollination.

Kernal length (L). Length of a rice grain, measured in millimeters.

Kernal width (W). Width of a rice grain, measured in millimeters.

Length/width (L/W) ratio. Determined by dividing the average length (L) by the average width (W).

Lodging. The percentage of plant stems that are leaning or have fallen to the ground before harvest. Lodging is determined by visual scoring, in which crops are rated from 0% (all plants standing) to 100% (all plant in plot lying flat on the soil surface). Lodged plants are difficult to harvest and reduce yield and grain quality. Lodging resistance is also called “straw strength”.

Milling yield. The total amount of milled rice (whole and broken kernels) recovered after milling (i.e., removal of hulls, bran, and germ). In contrast, head rice yield is the total amount of whole kernels recovered after milling. Both values are expressed as a weight percentage of the original paddy or rough rice sample that was milled. For example, for a sample of 100 grams of rough rice, a milling yield of 65/70 indicates that 65 grams of head rice and 70 grams of total milled rice were produced.

Pedigree. Refers to the lineage or genealogical descent of a plant.

Plant. As used herein, the term “plant” includes plant cells, plant protoplasts, and plant cell tissue cultures from which rice plants can be regenerated; plant calli, plant clumps and plant cells that are intact in plants; and parts of plants, such as embryos, pollen, ovules, flowers, glumes, panicles, leaves, stems, roots, root tips, anthers, and pistils.

Plant height. Measured in centimeters from the soil surface to the tip of the extended panicle at harvest.

Plant parts. Includes, without limitation, protoplasts, leaves, stems, roots, root tips, anthers, pistils, seed, grain, embryo, pollen, ovules, cotyledon, hypocotyl, pod, flower, shoot, tissue, petiole, cells, and meristematic cells.

Progeny. Includes an F₁ rice plant produced from the cross of two rice plants, as well as plants produced from subsequent generational crosses (e.g., F₂, F₃, F₄, F₅, F₆, F₇, F₈, F₉, and F₁₀) with the recurrent parental line.

Regeneration. Refers to the development of a plant from tissue culture.

Seeds. Includes seeds and plant propagules of all kinds including, but not limited to, true seeds, seed pieces, suckers, corms, bulbs, fruit, tubers, grains, cuttings, cut shoots and the like. However, in preferred embodiments, it refers to true seeds.

Trait. Refers to an observable and/or measurable characteristic of an organism. For example, the present invention describes plants that have a trait that make them resistant to fluazifop herbicides.

Transgenic. Describes an organism or cell that contains genetic material that has been artificially introduced.

Wild-type. When made in reference to a gene, “wild-type” refers to a functional gene common throughout a plant population and, thus, arbitrarily designated the “normal” or “wild-type” form of the gene.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a novel rice cultivar designated UADA1701081. The invention encompasses both the seeds of this cultivar and plants grown from these seeds. The invention further encompasses any rice plant having essentially all of the physiological and morphological characteristics rice cultivar UADA1701081.

As used herein, the term plant includes plant cells, plant protoplasts, plant cell tissue cultures from which rice plants can be regenerated, plant calli, plant clumps and plant cells that are intact in plants or parts of plants, such as embryos, pollen, ovules, flowers, glumes, panicles, leaves, stems, roots, root tips, anthers, pistils, and the like.

Development and Characterization of Rice Cultivar UADA1701081

Rice cultivar UADA1701081 (Poaceae Oryzea Oryza sativa L.) is a high yielding, short season, long-grain rice cultivar. UADA1701081 originated from the cross IRGA409/‘Rexmont’/5/‘Newbonnet’/3/‘Leb onnet’/CI9902//‘Labelle’/4/‘Millie’/6/Lebonnet/CI9902/3/‘Dawn’/CI9695//‘Starbonnet’/4/‘LaGrue’/5/‘Wells’ (cross #20052065) made in Stuttgart, Ark., in 2005. UADA1701081 was bred using hybridization, a combination of modified pedigree and bulk breeding methods, and is adapted to the Southern U.S. rice growing region. The experimental designation for early evaluation of UADA1701081 was STG09L-12-267, starting with a bulk of F₇ seed from the 2009 panicle row L-12-267. UADA1701081 was tested in the Arkansas Rice Performance Trials (ARPT) and the Cooperative Uniform Regional Rice Nursery (URRN) during 2017-2019 as entry UADA1701081 (RU number indicates URRN; 17 indicates that the year entered was 2017; 01 indicates Stuttgart, Ark.; and 081 its entry number).

UADA1701081 maturity falls between ‘Diamond’ and ‘Roy J’. UADA1701081 has straw strength similar to Diamond. On a relative straw strength scale (0=very strong straw, 9=very weak straw) UADA1701081, Diamond, ‘LaKast’, and Roy J rated 3, 3, 4 and 1, respectively. UADA1701081 has a height of 109 cm to the tip of the rice panicle, and it has a canopy plant height of 36 inches, which is similar to Diamond and LaKast. UADA1701081 has a lodging resistance similar to Diamond better than that of Wells. The nitrogen fertilizer requirements of UADA1701081 are 135 lbs/a.

Rough rice grain yields of UADA1701081 in 14 ARPT tests (2017-2019) have been 183 bushels/acre. For comparison, Diamond, LaKast, Roy J and RT XP753 yielded 205, 189, 193, and 230 bushels/acre, respectively. Data from the URRN conducted in Arkansas during 2017-2019, showed that UADA1701081 average grain yield of 226 bushels/acre compared favorably with those of Diamond, LaKast, and Roy J, at 239, 208, and 199 bushels/acre, respectively. Milling yields (mg g⁻¹ whole kernel:mg g⁻¹ total milled rice) at 120 mg g⁻¹ moisture measured at the ARPT during 2017-2018 averaged 500:700, 540:690, 550:690, 570:700, and 490:710, for UADA1701081, Diamond, LaKast, Roy J, and RT XL753, respectively. Milling yields for the URRN in Arkansas during the same period of time (2017-2018) averaged 590:70, 600:690, 600:700, and 620:710 for UADA1701081, Diamond, LaKast, and Roy J, respectively.

UADA1701081, like Drew, has the Pi-ta and Pi-km genes, which confer resistance to most of the common rice blast (Pyricularia grisea (Cooke) Sacc) races: D3-1, IB-17, IB-49, IC-17, IE-1, and IE-1K with summary ratings in greenhouse tests of 3, 0, 0, 0, 3 and 7.5, respectively, using the standard disease scale of 0=immune, 9=maximum disease susceptibility. UADA1701081 is rated MS to sheath blight (Rhizoctonia solani Kühn) which compares favorably with LaKast (MS), Diamond (S), Roy J (MS), using the standard disease R=resistant, MR=moderately resistant, MS=moderately susceptible, S=susceptible, and VS=very susceptible to disease. UADA1701081 is rated MS to false smut (Ustilaginoidea virens (Cooke) Takah), which compares favorably to Diamond (VS) and Lakast (S). UADA1701081 is rated S to bacterial panicle blight like Diamond (MS) and Roy J (S).

Plants of UADA1701081 have erect culms, green erect leaves, and glabrous lemma, palea, and leaf blades. The lemma and palea are straw colored with red apiculi, many of which fade to straw at maturity. Milled kernels of UADA1701081 are long at 7.13 mm, which is comparable to Diamond, Lakast, and Roy J, at 7.17, 7.56, and 7.31 mm, respectively. Individual milled kernel weights of UADA1701081, Diamond, LaKast, and Roy J averaged 21.0, 21.4, 22.3 and 21.1 mg/kernel, respectively, in the ARPT 2017-2018.

The endosperm of RU171081 is nonglutinous, nonaromatic, and covered by a light brown pericarp. Rice quality parameters indicate that UADA1701081 has typical southern U.S. long-grain rice cooking quality characteristics, as described by Webb et al. 1985. UADA1701081 has an average apparent starch amylose content of 23.1 g kg⁻¹ and an intermediate gelatinization temperature of 69.3° C.

The foundation seed field of UADA1701081 was rogued several times throughout the season. The variants that may be found in the release include any combination of the following: taller, shorter, earlier, later, glabrous or pubescent plants, as well as intermediate or long-grains and grains with extremely long awns. Other atypical plants may still be encountered in the variety. The total variants and/or off-types numbered less than 1 per 5000 plants.

The above-mentioned characteristics of rice cultivar UADA1701081 are based primarily on data collected in Stuttgart, Ark. and are summarized in Table 1. The results of the rice performance trials (ARPT 2017-2019 and URRN 2017-2019) are detailed in the Table 2-13. Tables 14-15 show grain quality data and Tables 16-17 show disease evaluation data.

TABLE 1 Distinguishing Characteristics of Morphology and Physiology Plant: Grain type: Long Days to maturity (Seeding to 50% heading): 89 (range 80-99 days) Plant height: 103 cm (range 99-109 cm) Plant color (at booting): Dark green Culm: Angle (degrees from perpendicular after flowering): Erect (less than 30°) Flag leaf (after heading): Pubescence: Glabrous Leaf angle (after heading): Erect Blade color (at heading): Dark green Panicle: Length: 22.2 cm Type: Intermediate Exsertion (near maturity): Moderately well Axis: Droopy Shattering (at maturity): Low (1-5%) Grain (spikelet): Awns (after full heading): Absent; a few with tip awns at high fertility or long and partly awned Apiculus color: Red Stigma color: White Lemma and palea color (at maturity): Straw Lemma and palea pubescence: Glabrous Grain (seed): Seed coat color: Light brown Scent: Nonscented Shape class (length/width ratio): Paddy: Long (3.4:1 and more) Brown: Long (3.1:1 and more) Milled: Long (3.0:1 and more) Size: 21.0 g/1000 seeds milled rice Disease resistance: Rice blast (Pyricularia grisea (Cooke) Sacc.): Moderately susceptible Sheath blight (Rhizoctonia solani Kuhn): Moderately susceptible False smut (Ustilaginoidea virens (Cooke) Takah.): Moderately susceptible Straight head: Moderately susceptible Bacterial panicle blight (Burkholderia glumae and B. gladioli): Susceptible Narrow brown leaf spot (Sphaerulina oryzina): Resistant

TABLE 2 UADA1701081 data summary from 2017 ARPT. (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County & Desha County) YIELD HEIGHT^(a) HEIGHT^(b) MATURITY MILLING VARIETY (BU/AC) (IN.) (IN.) (50% HD) HR:TOT UADA1701081 184 41 37 93 51:70 RU1701084 210 39 37 93 57:69 RU1701087 192 41 38 91 59:71 Diamond 206 42 38 91 56:69 LaKast 188 44 39 89 56:70 Roy J 196 42 40 94 60:70 ^(a)Plant height measured from to the tip of the panicle ^(b)Plant height is the canopy height not to tip of panicle

TABLE 3 UADA1701081 data summary from 2018 ARPT. (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County, & Desha County) YIELD HEIGHT^(a) MATURITY TEST WEIGHT MILLING VARIETY (BU/AC) (IN.) (50% HD) LBS/BU HR:TOT UADA1701081 183 36 85 39.6 49:70 RU1701084 201 35 87 40.0 54:69 RU1701087 186 37 85 39.9 57:70 Diamond 206 36 83 39.9 52:69 LaKast 187 36 82 40.0 53:67 Roy J 189 38 90 39.4 54:69 ^(a)Plant height is the canopy height not to tip of panicle

TABLE 4 UADA1701081 data summary from 2019 ARPT. (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County and Desha County) YIELD HEIGHT MATURITY TEST WT MILLING VARIETY (BU/AC) (IN.)^(a) (50% HD) (lbs/BU) HR:TOT* UADA1701081 183 35 86 40.5 54:71 RU1701084 206 34 86 40.0 56:70 RU171087 182 36 85 40.0 61:71 Diamond 204 35 85 40.5 58:70 LaKast 193 34 82 41.1 58:70 ^(a)Plant height is the canopy height not to tip of panicle

TABLE 5 UADA1701081 data summary from 2017-2019 ARPT. YIELD HEIGHT MATURITY TEST WT MILLING VARIETY (BU/AC) (IN.)^(a) (50% HD) (lbs/BU)^(c) HR:TOT^(d) UADA1701081 183 36 88 40.1 51:70 RU1701084 206 35 89 40.0 56:69 RU1701087 187 37 87 40.0 59:70 Diamond 205 36 86 40.2 56:70 LaKast 189 36 84 40.6 56:69 Roy J^(b) 193 39 92 — 57:70 ^(a)Plant height is the canopy height not to tip of panicle ^(b)2107 & 2018 data ^(c)test weight from 2018 & 2019 ^(d)2017 & 2018 data

TABLE 6 2017 ARPT mean by location (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County and Desha County) GRAIN YIELD (BU/AC) HEAD RICE(%): TOTAL RICE(%) VARIETY RREC NEREC PTES CLAY CHICOT AVG RREC NEREC PTES CLAY CHICOT AVG UADA1701081 183 192 163 197 184 184 61:72 57:70 47:69 53:72 37:69 51:70 RU1701084 201 205 201 229 217 210 59:70 61:68 54:67 61:70 50:68 57:69 RU1701087 203 192 169 205 190 192 61:73 60:70 61:71 60:71 50:70 59:71 Diamond 214 204 177 227 208 206 60:68 61:71 60:69 61:71 43:68 56:69 LaKast 194 179 172 201 197 188 57:69 60:72 58:70 61:71 44:70 56:70 Roy J 197 205 184 209 186 196 61:69 65:72 60:69 65:72 50:70 60:70

TABLE 7 2018 ARPT mean by location (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County and Chicot County) GRAIN YIELD (BU/AC) HEAD RICE(%):TOTAL RICE(%) VARIETY RREC NEREC PTES CLAY CHICOT AVG RREC NEREC PTES CLAY CHICOT AVG UADA1701081 182 154 186 199 192 183 60:70 38:69 48:70 42:72 59:70 49:70 RU1701084 204 198 204 196 201 201 60:68 50:68 52:69 50:71 58:69 54:69 RU1701087 183 157 183 204 202 186 58:69 53:68 57:70 59:72 59:71 57:70 Diamond 204 189 195 228 213 206 57:68 50:68 51:69 48:72 57:70 52:69 LaKast 191 161 190 213 181 187 58:70 42:54 52:70 54:72 58:71 53:67 RoyJ 193 178 190 204 178 189 52:66 55:69 54:70 50:72 58:71 54:69

TABLE 8 2019 ARPT mean by location (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; and Clay County) GRAIN YIELD (BU/AC) HEAD RICE(%): TOTAL RICE(%) VARIETY RREC NEREC PTES CLAY AVG RREC NEREC PTES CLAY AVG UADA1701081 215 179 148 191 183 56:70 64:71 35:70 62:72 54:71 RU1701084 225 197 179 222 206 56:67 65:70 40:69 64:71 56:70 RU1701087 211 171 156 189 182 57:70 60:68 61:72 64:72 61:71 Diamond 219 193 179 226 204 55:68 62:69 52:70 63:72 58:70 LaKast 213 202 161 203 195 57:70 60:69 49:70 64:72 58:70

TABLE 9 2017-2019 ARPT mean by location (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Clay County and Desha or Chicot County) GRAIN YIELD (BU/AC) HEAD RICE(%):TOTAL RICE(%)^(a) VARIETY RREC NEREC PTES CLAY CHICOT AVG RREC NEREC PTES CLAY CHICOT AVG UADA1701081 193 175 166 196 188 183 61:71 48:70 48:70 48:72 48:70 51:71 RU1701084 210 200 195 216 209 206 60:69 56:68 53:68 56:71 54:69 56:69 RU1701087 199 173 169 199 196 187 60:71 57:69 59:71 60:72 55:71 58:71 Diamond 212 195 184 227 211 205 59:68 56:70 56:69 55:72 50:69 55:70 LaKast 199 181 174 206 189 190 58:70 51:63 55:70 58:72 51:71 55:69 Roy J^(a) 195 192 187 206 182 192 57:68 60:71 57:70 58:72 54:71 57:70 ^(a)2017-2018 data

TABLE 10 2017 Arkansas URN data YIELD HEIGHT MATURITY MILLING VARIETY (BU/AC) (IN.) (50% HD) HR:TOT UADA1701081 219 43 84 59:69 RU1701084 238 42 83 60:69 RU1701087 224 46 82 60:69 Diamond 245 43 82 58:68 LaKast 201 46 80 56:69 Roy J 211 46 87 60:69

TABLE 11 2018 Arkansas URN data YIELD HEIGHT MATURITY MILLING VARIETY (BU/AC) (IN.) (50% HD) HR:TOT UADA1701081 230 42 81 59:71 RU1701084 220 41 83 62:69 RU1701087 218 45 79 59:69 Diamond 219 45 80 62:70 LaKast 215 47 76 63:71 Roy J 187 45 85 64:72

TABLE 12 2019 Arkansas URN data YIELD HEIGHT MATURITY MILLING VARIETY (BU/AC) (IN.) (50% HD) HR:TOT UADA1701081 228 45 91 65:73 RU1701084 234 41 93 59:73 RU1701087 245 43 90 63:72 Diamond 253 44 89 59:72 Roy J 202 45 95 56:72

TABLE 13 2017-2019 Arkansas URN data YIELD HEIGHT MATURITY MILLING VARIETY^(a) (BU/AC) (IN.) (50% HD) HR:TOT^(b) UADA1701081 226 43 85 61:71 RU1701084 231 41 86 60:70 RU1701087 229 45 84 61:70 Diamond 239 44 84 60:70 LaKast 208 47 78 60:70 Roy J 199 46 86 60:71 ^(a)LaKast only from 2017 & 2018 not included in 2019 test. Maturity may not be comparable for the LaKast and Roy J Milling from 2017 and 2018 for all entries

TABLE 14 2017-2018 quality data obtained from the Riceland Laboratory. Milling Data Satake Head Total Hull Bran Milling Moisture Chalk Length Width Thickness L:W Cultivar Yield Yield Yield Yield Whiteness Degree (%) (%) (mm) (mm) (mm) Ratio Diamond 64.7 69.9 17.7 12.4 41.0 96.1 9.1 1.41 7.17 2.12 1.74 3.4 LaKast 64.8 70.2 17.7 12.0 43.4 108.3 9.1 1.27 7.56 2.11 1.73 3.6 Roy J 64.6 69.9 17.7 12.4 40.7 96.4 9.4 1.09 7.31 2.08 1.74 3.5 UADA1701081 62.8 69.9 17.1 13.0 41.9 99.6 9.3 1.29 7.13 2.16 1.67 3.3 RU1701084 64.9 69.8 18.2 12.1 39.0 86.4 9.4 2.53 6.86 2.22 1.77 3.1 RU1701087 64.3 69.2 17.3 13.5 40.8 96.6 9.2 1.41 7.07 2.10 1.67 3.4 *These data are averages of the ARPT locations is a given year (2017 and 2018 five locations: Rice Research and Extension Center (RREC), Stuttgart, AR; Pine Tree Experiment Station (PTES) Colt, AR; Northeast Research and Extension Center, Keiser (NEREC), AR; Producer Field, Clay County (CLCO), AR; Producer Field, and Chicot County (CCO), AR.

TABLE 15 2017-2018 kernel characteristics. Weight Gel Temp Amylose RVA (rvu) Cultivar (g) (° C.) (%) Peak Trough Breakdown Final Setback Diamond 21.4 69.3 23.7 263.2 134.0 129.2 271.0 7.9 LaKast 22.3 68.7 23.9 269.8 148.3 121.6 287.6 17.7 Roy J 21.1 68.8 24.2 259.0 132.0 126.9 267.7 8.8 UADA1701081 21.0 69.3 23.1 255.5 139.3 116.3 274.5 19.0 RU1701084 21.8 68.8 23.5 250.3 129.4 120.8 263.7 13.4 RU1701087 19.9 70.7 25.6 192.2 101.3 90.9 219.6 27.4 *These data are averages of the ARPT locations is a given year (2017 and 2018 five locations: Rice Research and Extension Center (RREC), Stuttgart, AR; Pine Tree Experiment Station (PTES) Colt, AR; Northeast Research and Extension Center, Keiser (NEREC), AR; Producer Field, Clay County (CLCO), AR; Producer Field, and Chicot County (CCO), AR. Disease Evaluations of Rice Cultivar UADA1701081

Varietal resistance is the most efficient and reliable means of controlling rice diseases. Conservation and improvement of disease resistance is a continuous endeavor basic to varietal development. Incorporation of existing and new resistance sources is a complex process limited by several variables. The rice disease research program routinely evaluates breeding program entries to provide disease data required for superior variety development. Our objectives are to increase varietal disease resistance and to define disease liabilities of new varieties released for rice production in Arkansas.

Rice diseases are mostly rated visually on a 0-9 scale to estimate degree of severity. Numerical data is often converted to this scale. A rating of zero indicates complete disease immunity. A rating of one to three indicates resistance where little loss occurs and in the case of rice blast pathogen growth is restricted considerably. Conversely, a nine rating indicates maximum disease susceptibility, which typically results in near complete plant death and/or yield loss. Depending upon the disease in question, a disease rating of four to six is usually indicative of acceptable disease resistance under conditions slightly favoring the pathogen. Numerical ratings are sometimes converted to letter symbols where 0-3=R (resistant), 3-4=MR (moderately resistant), 5-6=MS (moderately susceptible) 7=S (susceptible) and 8-9 VS (very susceptible). Exceptions to established ratings do occur unexpectedly as disease situations change.

These data come from several sources. Advanced and promising breeding lines are normally evaluated by researchers in other states. It is not unusual for ratings to vary with location and year due to environmental differences and research procedures. Ratings within a source traditionally have been consistent.

Greenhouse blast tests are the primary means of screening large number of entries for varietal reaction to the many blast races occurring in the production areas. Although results are quite variable and testing conditions tends to overwhelm any field resistance present in the entry, this test provides an accurate definition of the fungus-variety genetics. Blast field nurseries, utilizing both natural and lab produced inoculum, are established in an effort to better define blast susceptibility under field conditions. Since field nursery is also quite variable, new techniques are currently being developed and evaluated to better estimate cultivar field resistance to blast.

Field nurseries are established and artificially inoculated to provide a uniform disease pressure for evaluations under field conditions. Grower nurseries are established operate in an effort to evaluate disease reactions in grower fields under current production practices. Over time these nurseries document variety performance under adverse disease conditions in Arkansas production fields.

Below, Tables 16-17 show disease evaluation data.

TABLE 16 Summary of available leaf blast rating data from plants inoculated with the indicated race using standard greenhouse techniques in 2019. Note: UADA1701081 has the Pi-ta and Pi-km genes for blast resistance. Year IB-1 IB-17 IB-49 IC-17 IE-1K IE-1 2019 4 0 0 0 7.5 N/A 2017 3.0 0 3.0 0 4.5 3.0

TABLE 17 Rice variety reactions¹ to diseases (2018-2019). Narrow Bacterial Brown Black Sheath Panicle Leaf Stem Kernel False Sheath Cultivar Blight Blast Straighthead Blight Spot Rot Smut Smut Lodging Rot UADA1701081 MS MS MS S R MS Diamond S S MS S S VS MS LaKast MS S MS MS MS S S S MS MS Roy J MS S S S R S VS S MR MS RiceTec XL753 MS R MS MR R MS S MS S RiceTec XP760 MS MR MR R MS VS S Wells S S S S S VS S S MS MS ¹Reaction: R = Resistant; MR = Moderately Resistant; MS = Moderately Susceptible; S = Susceptible; VS = Very Susceptible. Reactions were determined based on historical and recent observations from test plots and in grower fields across Arkansas. In general, these reactions would be expected under conditions that favor severe disease development including excessive nitrogen rates (most diseases) or low flood depth (blast). Methods

This present invention provides methods for producing rice plants. In some embodiments, these methods involve crossing a first parent rice plant with a second parent rice plant wherein either the first or second parent rice plant is a rice plant of the line UADA1701081. Further, both first and second parent rice plants can come from the rice cultivar UADA1701081. Still further, this invention also is directed to methods for producing a rice cultivar UADA1701081-derived rice plant by crossing rice cultivar UADA1701081 with a second rice plant and growing the progeny seed, and repeating the crossing and growing steps with the rice cultivar UADA1701081-derived plant from 0 to 7 times. Thus, any such methods using the rice cultivar UADA1701081 are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using rice cultivar UADA1701081 as a parent are within the scope of this invention, including plants derived from rice cultivar UADA1701081. Advantageously, the rice cultivar is used in crosses with other, different, rice cultivars to produce first generation (F₁) rice seeds and plants with superior characteristics.

In some embodiments, a UADA1701081 progeny plant is selected that has molecular markers, morphological characteristics, and/or physiological characteristics in common with UADA1701081 (e.g., those listed in Table 1). Techniques such as RFLP-enhanced selection, genetic marker enhanced selection (e.g., SSR markers), and the making of double haploids may be utilized to identify progeny that share particular traits with UADA1701081.

Further, this invention provides methods for introducing a desired trait into rice cultivar UADA1701081. This may be accomplished using traditional breeding methods, such as backcrossing (see Breeding Methods section below). Alternatively, the desired trait may be introduced by transforming the rice cultivar with a transgene (see Transformation Methods section below). The transgenic cultivar produced by these methods may be crossed with another cultivar to produce a new transgenic cultivar. Alternatively, the transgene incorporated by these methods could be moved into another cultivar using traditional backcrossing techniques.

Optionally, any of the disclosed methods may further comprise additional steps involving producing rice seed from the resulting rice plants and/or planting the rice seed.

The present invention encompasses all plants, or parts thereof, produced by the methods described herein, as well as the seeds produced by these plants. Further, any plants derived from rice cultivar UADA1701081 or produced from a cross using cultivar UADA1701081 are provided. This includes genetic variants, created either through traditional breeding methods or through transformation, as well as plants produced in a male-sterile form. Notably, this includes gene-converted plants developed by backcrossing. Any of the seeds, plants, or plant parts provided may be utilized for human food, livestock feed, and as a raw material in industry.

The present invention also encompasses progeny of rice cultivar UADA1701081 comprising a combination of at least two UADA1701081 traits selected from those listed in the Tables and Detailed Description of the Invention, wherein the progeny rice plant is not significantly different from UADA1701081 for said traits, as determined at the 5% significance level when grown in the same environment. One of skill in the art knows how to compare a trait between two plant varieties to determine if there is a significant difference between them (Fehr and Walt, Principles of Cultivar Development, pp. 261-286 (1987)). Molecular markers or mean trait values may be used to identify a plant as progeny of UADA1701081. Alternatively, progeny may be identified through their filial relationship with rice cultivar UADA1701081 (e.g., as being within a certain number of breeding crosses of rice cultivar UADA1701081). For example, progeny produced by the methods described herein may be within 1, 2, 3, 4, or 5 breeding crosses of rice cultivar UADA1701081.

Tissue Culture

The present invention provides tissue cultures of regenerable cells or protoplasts produced from rice cultivar UADA1701081. As is well known in the art, tissue culture of rice can be used for the in vitro regeneration of a rice plant. Thus, such cells and protoplasts may be used to produce plants having the physiological and morphological characteristics of rice variety UADA1701081. The rice plants regenerated by these methods are also encompassed by the present invention.

As used herein, the term “tissue culture” describes a composition comprising isolated cells or a collection of such cells organized into parts of a plant. Exemplary tissues for culture include protoplasts, calli, plant clumps, and plant cells that can be grown in culture, or parts of plants, such as embryos, pollen, flowers, seeds, pods, leaves, stems, roots, root tips, and anthers. Culture of various rice tissues and regeneration of plants therefrom is well known in the art.

Breeding Methods

The goal of rice breeding is to develop new, superior rice cultivars and hybrids. A superior cultivar is produced when a new combination of desirable traits is formed within a single plant variety. Desirable traits may include higher seed yield, resistance to diseases and insects, better stems and roots, tolerance to low or high temperatures, herbicide resistance, and better agronomic characteristics or grain quality.

The breeding methods used with the present invention may involve a single-seed descent procedure, in which one seed per plant is harvested and used to plant the next generation. Alternatively, the methods may utilize a multiple-seed procedure, in which one or more seeds harvested from each plant in a population is threshed together to form a bulk which is used to plant the next generation.

Use of rice cultivar UADA1701081 in any plant breeding method is encompassed by the present invention. The choice of a breeding or selection method will depend on several factors, including the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F1 hybrid cultivar, pureline cultivar). Popular selection methods include pedigree selection, modified pedigree selection, mass selection, recurrent selection, backcrossing, or a combination thereof.

Pedigree selection is commonly used for the improvement of self-pollinating crops. Two parents are crossed to produce an F₁ population. An F₂ population is produced by selfing one or several F₁'s. Selection of the best individuals may begin in the F₂ population; then, beginning in the F₃ generation, the best individuals in the best families are selected. Replicative testing of families can begin in the F₄ generation to make selection of traits with low heritability more effective. At an advanced stage of inbreeding (e.g., F₆ or F₇), the best lines are tested for potential release as new cultivars.

Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population, which is often subjected to additional cycles of selection.

Backcrossing is commonly used to transfer genes for highly heritable traits into a desirable homozygous cultivar or inbred line. The term “backcrossing” refers to the repeated crossing of hybrid progeny back to one of the parental plants, referred to as the recurrent parent. The plant that serves as the source of the transferred trait is called the donor parent. After the initial cross, individuals possessing the transferred trait are selected and repeatedly crossed to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent along with the trait transferred from the donor parent.

Transformation Methods

As is noted above, the present invention provides plants and seeds of rice cultivar UADA1701081 in which additional traits have been transferred. While such traits may be selected for using traditional breeding methods, they may also be introduced as transgenes. “Transgenes” include both foreign genes and additional or modified versions of native genes. Plants can be genetically engineered to have a wide variety of traits of agronomic interest including, without limitation, male sterility, waxy starch, herbicide resistance, resistance for bacterial, fungal, or viral disease, insect resistance, male fertility, enhanced nutritional quality, industrial usage, yield stability, and yield enhancement. Many examples of genes that confer such traits have been described in the literature and are well known in the art. For example, the transgene may confer resistance to an herbicide selected from the group consisting of: glyphosate, sulfonylurea, imidazolinone, dicamba, glufosinate, phenoxy proprionic acid, L-phosphinothricin, cyclohexone, cyclohexanedione, triazine, 2,4-Dichlorophenoxyacetic acid, hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitors, and benzonitrile.

Transgenes are typically introduced in the form of an expression vector. As used herein, an “expression vector” is DNA comprising a gene operatively linked to a regulatory element (e.g., a promoter). The expression vector may contain one or more such gene/regulatory element combinations. The expression vector may also include additional sequences, such as a signal sequence or a tag, that modify the protein produced by the transgene. The vector may be a plasmid, and can be used alone or in combination with other plasmids.

Expression vectors include at least one genetic marker operably linked to a regulatory element (e.g., a promoter) that allows transformed cells containing the vector to be recovered by selection. In some embodiments, negative selection (i.e., inhibiting growth of cells that do not contain the selectable marker gene) it utilized. Negative selection markers include, for example, genes that result in detoxification of a chemical agent (e.g., an antibiotic or an herbicide) and genes that result in insensitivity to an inhibitor. Exemplary negative selection genes include neomycin phosphotransferase II (nptII), hygromycin phosphotransferase, gentamycin acetyl transferase, streptomycin phosphotransferase, and aminoglycoside-3′-adenyl transferase. In other embodiments, positive selection (i.e., screening for the product encoded by a reporter gene) is utilized. Exemplary reporter genes include β-glucuronidase, β-galactosidase, luciferase, chloramphenicol acetyltransferase, and Green Fluorescent Protein (GFP).

Transgene expression is typically driven by operably linking the transgene to a promoter within the expression vector. However, other regulatory elements may also be used to drive expression, either alone or in combination with a promoter. As used herein, a “promoter” is a region of DNA upstream of a transcription start site that is involved in recognition and binding of RNA polymerase for transcription initiation. Any class of promoter may be selected to drive the expression of a transgene. For example, the promoter may be “tissue-specific”, “cell type-specific”, “inducible”, or “constitutive”. Those of skill in the art know how to select a suitable promoter based the particular circumstances and genetic engineering goals.

Methods for producing transgenic plants are well known in the art. General descriptions of plant expression vectors, reporter genes, and transformation protocols can be found in Gruber, et al., “Vectors for Plant Transformation”, in Methods in Plant Molecular Biology & Biotechnology in Glich, et al., (Eds. pp. 89-119, CRC Press, 1993). General methods of culturing plant tissues are provided for example by Maki, et al., “Procedures for Introducing Foreign DNA into Plants” in Methods in Plant Molecular Biology & Biotechnology, Glich, et al., (Eds. pp. 67-88 CRC Press, 1993); and by Phillips, et al., “Cell-Tissue Culture and In-Vitro Manipulation” in Corn & Corn Improvement, 3rd Edition; Sprague, et al., (Eds. pp. 345-387 American Society of Agronomy Inc., 1988). Methods of introducing expression vectors into plant tissue include direct gene transfer methods, such as microprojectile-mediated delivery, DNA injection, and electroporation, as well as the direct infection or co-cultivation of plant cells with Agrobacterium tumefaciens, described for example by Horsch et al., Science, 227:1229 (1985). Descriptions of Agrobacterium vector systems and methods for Agrobacterium-mediated gene transfer are provided by Gruber, et al., supra.

REFERENCES

-   Webb, B. D., C. N. Bollich, H. L. Carnahan, K. A. Kuenzel.,     and K. S. McKenize. 1985. Utilization characteristics and qualities     of United States rice. p. 25-35. In: Rice grain quality and     marketing. IRRI, Manila, Philippines

DEPOSIT INFORMATION

A deposit of the University of Arkansas Division of Agriculture Rice Research and Extension Center proprietary rice cultivar UADA1701081 disclosed above and recited in the appended claims has been made with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va. 20110. The date of deposit was Jan. 4, 2021. The deposit of 2,500 seeds was taken from the same deposit maintained by the University of Arkansas Division of Agriculture Rice Research and Extension Center (2900 Hwy 130 E., Stuttgart, AR 72160) since prior to the filing date of this application. All restrictions will be irrevocably removed upon granting of a patent, and the deposit is intended to meet all of the requirements of 37 C.F.R. §§ 1.801-1.809. The ATCC Accession Number is PTA-126947. The deposit will be maintained in the depository for a period of thirty years, or five years after the last request, or for the enforceable life of the patent, whichever is longer, and will be replaced as necessary during that period. 

What is claimed is:
 1. A rice seed of the cultivar ‘UADA1701081,’ a representative sample of seed of said cultivar having been deposited under ATCC Accession No. PTA-126947.
 2. A rice plant, or a part thereof, produced by growing the seed of claim
 1. 3. A rice plant, or a part thereof, having all of the physiological and morphological characteristics of the rice plant of claim
 2. 4. Pollen or an ovule of the plant of claim
 2. 5. A method for producing rice plants, said method comprising planting a plurality of rice seeds as recited in claim 1 under conditions favorable for the growth of rice plants.
 6. The method of claim 5, further comprising the step of producing rice seed from the resulting rice plants.
 7. A rice seed produced by the method of claim
 6. 8. A tissue culture of regenerable cells or protoplasts produced from the rice plant of claim
 2. 9. The tissue culture of claim 8, wherein said cells or protoplasts are produced from a tissue selected from the group consisting of embryos, meristematic cells, pollen, leaves, anthers, roots, root tips, pistils, anthers, cotyledon, hypocotyl, panicles, flowers, seeds, and stems.
 10. A rice plant regenerated from the tissue culture of claim 8, said rice plant having all of the morphological and physiological characteristics of ‘UADA1701081’.
 11. A method for producing an F₁ hybrid rice plant, said method comprising crossing a first parent rice plant with a second parent rice plant, wherein the first parent rice plant or the second patent rice plant is the rice plant of claim
 2. 12. The method of claim 11, further comprising the step of producing rice seed from the resulting rice plant.
 13. The method of claim 11, wherein the second parent rice plant is transgenic.
 14. A method comprising transforming the rice plant of claim 2 or cell thereof with a transgene, wherein the transgene confers at least one trait selected from the group consisting of: herbicide resistance; insect resistance; resistance to bacterial, fungal, or viral disease; modified fatty acid metabolism; modified carbohydrate metabolism; and male sterility.
 15. A rice plant or cell thereof produced by the method of claim
 14. 16. An herbicide resistant rice plant produced by the method of claim 14, wherein the gene confers resistance to a herbicide selected from the group consisting of glyphosate, sulfonylurea, imidazolinone, dicamba, glufosinate, phenoxy proprionic acid, L-phosphinothricin, cyclohexone, cyclohexanedione, triazine, 2,4-Dichlorophenoxyacetic acid, hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitors and benzonitrile.
 17. A method of introducing a desired trait into rice cultivar ‘UADA1701081,’ said method comprising the steps of: (a) crossing plants as recited in claim 2 with plants of another rice line expressing the desired trait, to produce progeny plants; (b) selecting progeny plants that express the desired trait, to produce selected progeny plants; (c) crossing the selected progeny plants with plants from the ‘UADA1701081 parental line to produce new progeny plants; (d) selecting new progeny plants that express the desired trait; and (e) repeating steps (c) and (d) three or more times in succession, to produce selected higher generation backcross progeny plants that express the desired trait.
 18. The method of claim 17, additionally comprising the step of planting a plurality of rice seed produced by selecting higher generation backcross progeny plants under conditions favorable for the growth of rice plants and optionally comprising the step of producing rice seed from the resulting rice plants. 